Our approach to analyzing mechanisms of visuomotor coordination is two-fold: "top-down", to offer a coordinated control program of interacting schemas (concurrently active programs suitably structured for action-perception systems) to model behavior noted by neuroethologists; and "bottom-up", to provide detailed models of neural networks which are consistent with known anatomy and physiology, but which involve additional assumptions, amenable to experimental test, to yield a network capable of exhibiting appropriate behavior. Where possible, we implement a family of models, rather than a single model, to facilitate computer experiments and animal experiments which may discriminate between alternative mechanisms. Specifically, we plan to conduct studies of the following subtopics: (1) Modelling tectum-pretectum interactions subserving pattern-recognition in anurans; (2) Detailed neural modelling of retina; (3) Modelling patterns of behavior in frog and toad while developing a theory of motor schemas and their coordination for orientation, sidestepping, snapping, etc.; and (4) Developing mathematical and computer methodology for exploring a model-family to determine which subset of models approximates satisfaction of a given set of constraints. The work will make modelling tools available for the analysis of large brain systems. Our research plan has build into it structures which ensure that these tools are accessible to neurophysiologists, neuroanatomists and neuroethologists, while also facilitating a full exchange of ideas with the computer science community (artificial intelligence, simulation methodology, interactive computer graphics, etc.).